Standard shell-model techniques of constructing and diagonalizing Hamiltonians in finite Hilbert spaces have been used to treat the N=50 isotones with an expanded model space and a new empirical effective interaction. A vector space with active 0$f_{5/2}$, 1$p_{3/2}$, 1$p_{1/2}$, and 0$g_{9/2}$ proton orbits is used to model the low-lying excitations of these nuclei. The effective interaction is obtained by varying 35 parameters, distributed over the 65 two-body matrix elements and four single particle energies of the model space, to fit over 170 experimental energy levels in nuclei from ${}_{}{}^{82}{}_{}{}^{}\mathrm{Ge}$ through ${}_{}{}^{96}{}_{}{}^{}\mathrm{Pd}$. Nearly all of the experimental level energies of N=50 nuclei involved in the fit are well reproduced by the final interaction.

• Received 5 October 1987

DOI:https://doi.org/10.1103/PhysRevC.37.1256